Induced answering method and system for circuit switching-based telephony

ABSTRACT

Induced answering method and system for CS-based telephony. A user terminal ( 5 ) for communication over a telecommunications network ( 3 ) includes at least a CS-telephony device (CSO) for processing CS-based telephony signals (CS 1 , CS 2 ), the CS-based telephony signals being received and transmitted over a circuit switched bearer service. The user terminal is arranged for receiving an additional answer-related signal (PS 1 ; CS 3 ), the additional answer-related signal being associated with an incoming CS-alert signal (CS 1 ) of an incoming call. Further, the user terminal is arranged for transmitting a response signal or CS-answer signal (CS 2 ) over the circuit switched bearer service in response to information included in, or derived from, the additional answer-related signal.

FIELD OF THE INVENTION

The present invention relates to a user terminal as defined in claim 1.Also, the present invention relates to a method for answering CS-basedtelephony. Moreover, the present invention relates to a network exchange(or network service or network application server) and to acall-initiating terminal.

The present invention also relates to a computer program for a userterminal.

BACKGROUND OF THE INVENTION

In circuit-switched (CS) telephony, a set-up of a call between partiescomprises a number of steps. A call is initiated by a first party A, whodials on his A-terminal a telephone number of a B-terminal of secondparty B. Then, the telephony network routes the call to the B-terminalby using the information of the dialed telephone number. Next, the callis announced to party B by a signal generated on the B-terminal. Then,the B-party can answer the call by some interaction with the B-terminal.The B-terminal signals the network that the call is accepted. After theanswer generated by the B-terminal, the call is connected between theA-terminal and the B-terminal and a speech communication between partiesA and B is established.

This set-up of a call is implemented in both the wired and the mobilenetwork. Both the A-terminal and B-terminal may be a wired or mobiletelephone.

From the prior art a specification for mobile CS-telephony is known (GSMTS 04.07 version 7.3.0, chapter 6.2) which describes a sequence ofstates of a finite state machine of a telephone device during set-up,progress and termination of a call. FIG. 1 shows a part of the CS-callstate diagram 1 from the prior art.

The finite state machine of the telephone (B-terminal) can be in anumber of various states. Normally, when the telephone is idle and notin communication, the state of the telephone is the “null” state 10.

From the network as an incoming signal a call request by the A-terminalmay be received. Due to this signal, the finite state machine changesits state to a “call received” state 20. The finite state machinearrives at the “call received” state 20 through some intermediatestate(s) 15. In this state the user (party B) of the B-terminal isnotified of the incoming call. Due to a user generated answer, e.g.pressing an “acknowledge” key on the keypad of the B-terminal, thefinite state machine changes to an active state 30, in which speechcommunication between the party A of the A-terminal and the party B ofthe B-terminal can be executed. The action of a user generated answer tothe incoming call is schematically indicated by block A1, connected by adotted arrow-line to the “call received state” 20.

The finite state machine arrives at the “active” state 30 through anintermediate state 25. At the same time, a CS-call answer signal isreturned to the exchange to establish the speech communication phase.

Upon termination of the call, the finite state machine changes to the“null” state 10, possibly through some further intermediate state(s) 35.At this time, termination of the call is indicated to the exchange.

In the prior art, the party B is required to activate the B-terminal byperforming some manipulation of the B-terminal, e.g., by pressing some“acknowledge” button on the terminal.

The above mentioned method of answering the incoming call adverselyrestricts the usability and functionality of the telephone, i.e., themethod of the prior art may limit user-directed services.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a terminal which hasimproved answering capabilities in view of the prior art.

To solve this object, the present invention provides a user terminal forcommunication over a telecommunications network comprising at least aCS-telephony device for processing CS-based telephony signals, theCS-based telephony signals being received and transmitted over a circuitswitched bearer service;

the user terminal being arranged for receiving an additionalanswer-related signal, the additional answer-related signal beingassociated with an incoming CS-alert signal of an incoming call;

the user terminal being arranged for transmitting a response signal orCS-answer signal over the circuit switched bearer service in response toinformation comprised in, or derived from, the additional answer-relatedsignal.

Advantageously, the present invention provides a possibility forautomatic answering an incoming call on the user terminal, which doesnot require a user interaction.

Also, the present invention relates to a network service on atelecommunications network comprising at least a circuit switched bearerservice for receiving and transmitting CS-based telephony signals; thecircuit switched bearer service being arranged for sending an CS-alertsignal of an incoming call to a user terminal; the network service beingarranged for sending an additional answer-related signal to the userterminal, the additional answer-related signal being associated with theCS-alert signal of the incoming call and being arranged for causing theuser terminal to provide a response signal or CS-answer signal over thecircuit switched bearer service.

Moreover, the present invention relates to a call initiating terminal orA-terminal for communication over a telecommunications networkcomprising a CS-telephony device for processing CS-based telephonysignals, the CS-based telephony signals being received and transmittedover a circuit switched bearer service; the call initiating terminalbeing arranged for transmitting an additional answer-related signalbeing associated with a transmitted CS-call setup signal for an outgoingcall with a user terminal, the additional answer-related signalcomprising information on the outgoing call, which causes the receivinguser terminal to provide a response signal or CS-answer signal over thecircuit switched bearer service.

Furthermore, the present invention relates to a method for communicationover a telecommunications network comprising:

-   -   processing CS-based telephony signals, the CS-based telephony        signals being received and transmitted over a circuit switched        bearer service;    -   receiving an additional answer-related signal being associated        with an incoming CS-alert signal of an incoming call;    -   transmitting a response signal or CS-answer signal over the        circuit switched bearer service in response to information        comprised in, or derived from, the additional answer-related        signal.

Also, the present invention relates to a computer program for a userterminal for communication over a telecommunications network (3), theuser terminal comprising at least a CS-telephony device for processingCS-based telephony signals, the CS-based telephony signals beingreceived and transmitted over a circuit switched bearer service; whereinthe user terminal further comprises a processing unit and memory, thememory being coupled with the processing unit,

the computer program after being loaded, enabling the processing unit tocontrol the following functions of the user terminal:

-   -   receiving an additional answer-related signal associated with an        incoming CS-alert signal of an incoming call;    -   transmitting a response signal or CS-answer signal over the        circuit switched bearer service in response to information        comprised in, or derived from, the additional answer-related        signal.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be explained in more detail below with reference to afew drawings in which illustrative embodiments of the invention areshown. It will be appreciated by the person skilled in the art thatother alternative and equivalent embodiments of the invention can beconceived and reduced to practice without departing from the true spiritof the invention, the scope of the invention being limited only by theappended claims.

FIG. 1 shows a part of a CS-call state diagram from the prior art;

FIG. 2 shows schematically answering procedures in a terminal from theprior art;

FIG. 3 shows schematically a terminal capable of using the answeringmethod according to the present invention;

FIG. 4 shows a CS-call state diagram in accordance with the presentinvention;

FIG. 5 shows a signal flow in accordance with the answering method ofthe present invention;

FIG. 6 shows a further signal flow in accordance with the answeringmethod of the present invention;

FIGS. 7 a, 7 b, 7 c show still further signal flows in accordance withthe answering method of the present invention;

FIG. 8 shows a signaling diagram for a further embodiment of theanswering method of the present invention, and

FIG. 9 shows a CS-call state diagram in a further embodiment of theanswering method of the present invention.

Throughout the figures entities with the same reference number refer toidentical entities as shown in the other figures.

DESCRIPTION OF EMBODIMENTS

FIG. 2 shows schematically an answering procedure in a terminal 2 fromthe prior art.

The terminal 2 is typically a mobile telephone but may also be a wiredtelephone. The terminal 2 is arranged for communication over atelecommunications network 3.

The terminal 2 as an electronic device comprises a CS-telephony deviceCS0 which is arranged for processing CS-based telephony signals.CS-based telephony signals may be implemented, for example, by means ofthe DTAP protocol (Direct Transfer Application Part) as used in GSM(Global System for Mobile communications). Further, the terminal 2 maycomprise a further device D0 which may be arranged for providing agraphical user interface (GUI) and for providing execution of one ormore applications which may be executed locally, and possibly but notnecessarily within the GUI. The further device D0 typically comprisesmemory for storing data and/or applications.

In the CS-telephony device CS0 a finite state machine FSM is presentwhich is capable of managing CS-based telephony functions.

The answering procedure shown for the terminal 2 corresponds with theCS-call state diagram of FIG. 1.

From the network 3 a CS alert signal CS1 is provided to the terminal 2to indicate a call-request for an incoming call. As described above withreference to FIG. 1, the finite state machine FSM provides anotification of the incoming call to the user of the terminal 2.

The user responds by some action e.g. pressing an “acknowledge” button,depicted here as an action signal A1.

The signal A1 from the user action is provided to the finite statemachine FSM. The finite state machine FSM now prepares for speechcommunication in “active” state 30 by an acceptance signal A2. At thistime, a CS-based answer signal CS2 is sent to the network 3 to indicatethe call is being answered and a speech communication 7 is opened withthe call initiating terminal or A-terminal (not shown).

FIG. 3 shows a user terminal 5 in accordance with the present invention.

In FIG. 3 entities with the same reference number refer to identicalentities as shown in the preceding figures.

In the present invention it is recognized that an automatic answer maybe provided by a user terminal 5 when in relationship with the CS alertsignal CS1 an additional packet switched signal PS1 of a packet switchednetwork source (on the network 3) is provided to the user terminal 5 ofthe present invention.

The user terminal 5 of the present invention comprises electroniccircuitry in which the CS-telephony device CS0 and a packet switcheddata processing device PS0 reside. Devices CS0 and PS0 are schematicallydepicted by dashed-line rectangles. Further, the user terminal 5 maycomprise the further device D0 as described above which may be arrangedfor providing a graphical user interface (GUI) and (locally executable)applications related to the GUI.

Packet switched signals PS1 are, for example, implemented by means ofthe Internet Protocol (IP).

Within the CS-telephony device CS0 the finite state machine FSM islocated.

Within the packet switched data processing device PS0 a processingapplication HA for processing a packet switched signal is located. Also,a storage device or memory MP for storing data relating to theadditional packet switched signal PS1 may be located here.

The processing application HA has an output which is in connection 40 tothe finite state machine FSM for transmitting information signals fromthe processing application HA to the finite state machine FSM. Theprocessing application is capable of deriving information from theadditional packet switched signal PS1. Such information signals compriseat least an answering control signal ACS.

The finite state machine FSM is capable of changing its state inrelation to the answering control signal ACS received from theprocessing application HA, as will be explained in more detail below.

A network service (or network application server) NS on the network 3 iscapable of providing the CS alert signal CS1 in combination with theadditional packet switched signal PS1 to the user terminal 5.

Within the network 3 the signals CS1 and PS1 are transmitted over theirrespective bearer services. The CS-alert signal CS1 is transmitted overa first circuit-switch based bearer service. The packet switched signalPS1 is transmitted over a second packet-switch based bearer service.

The CS alert signal CS1 is guided to the CS-telephony device CS0. The CSalert signal CS1 will have an interaction with the finite state machineFSM as described above with reference to FIGS. 1 and 2. The finite statemachine FSM will change its state to the call received state 20 (if notbusy).

The finite state machine FSM is arranged to expect an additional packetswitched signal PS1 in conjunction with the receipt of the CS-alertsignal CS1. In one embodiment, the finite state machine FSM derives fromthe CS-alert signal CS1 that such an additional packet switched signalPS1 is to be expected. For example, this can be based on the receivedCaller Line Identity signal or a modification of the CS-alert signalCS1. The received Caller Line Identity signal or modification of theCS-alert signal CS1 may be compared to some stored data in the memory MPto determine if the CS-alert signal relates to a relevant networkservice and if a related additional packet switched signal PS1 can beexpected. In another embodiment, the finite state machine FSM may bearranged to expect to receive a related additional packet switchedsignal PS1 within a (fixed) predetermined interval of time. Whileexpecting the additional packet switched signal PS1, the finite statemachine FSM may be arranged to postpone generation of an alarm (audible,visible or tactile) for the user. The predetermined interval of time maybe such that the CS-alert signal CS1 and the packet switched signal PS1are received substantially simultaneously at the user terminal 5.

Also, it is feasible that the packet switched signal PS1 arrives beforethe CS-alert signal CS1, but is withheld until arrival of thecorresponding CS-alert signal CS1.

After receipt, the additional packet switched signal PS1 is guided tothe processing application HA in the packet switched data processingdevice PS0. The additional packet switched signal PS1 contains at leastanswering-related data that relate to the “ongoing” CS alert signal CS1.The processing application HA is arranged to determine from theanswering-related data in the packet switched signal PS1 if the networkservice requests that an automatic answer by the user terminal 5 isexecuted.

If an automatic answer is requested the processing application HA mayprovide the answering control signal ACS over the connection 40 to thefinite state machine FSM.

Upon receipt of the answering control signal ACS, the finite statemachine FSM changes it's state by transition from the “call received”state 20 through the intermediate state 25 to the “active” 30 state.

By consequence, the user terminal 5 provides the CS-answer signal CS2 tothe network 3 that the pending call is answered. Speech communication 7can be initiated.

In the manner as described above the additional packet switched signalPS1 provides a network induced answer for the CS-telephony based deviceCS0.

In accordance with the present invention, the transition from the “callreceived” state 20 to the “active” state 30 is triggered by a networkinduced answer (provided by the additional packet switched signal PS1)or by call acceptance by the mobile terminated user of the user terminal5.

The sequel of the established call may be as described above withreference to FIGS. 1 and 2.

FIG. 4 shows a CS-call state diagram 4 for the finite state machine ofthe user terminal 5 in accordance with the present invention.

The finite state machine FSM of the user terminal 5 is very similar tothe finite state machine of the prior art, except that additionally thefinite state machine FSM is capable of accepting a primitive ACS in theCS-call state. Primitive ACS is derived from the answering controlsignal ACS that was generated by the processing application HA. Theprimitive ACS may influence (dotted line) the finite state machine FSMto change the state from “call received” state 20 to the “active” 30state.

The step of determining by the processing application HA that anautomatic answer by the user terminal 5 is to be executed requires thatthe CS-alert signal CS1 and the additional packet switched signal PS1are correlated in some way. For example, the additional packet switchedsignal PS1 may contain data that relate to the CS-alert signal CS1, suchas the Calling Line Identity (CLI) of the party A which typically isincluded in the CS-alert signal CS1. Also, the CS-alert signal CS1 maycontain some data to indicate that the additional packet switched signalPS1 will be sent along.

Moreover, from the additional packet switched signal PS1 the processingapplication may derive an identification of the network service NS thatsent the combined CS-alert signal CS1 and the additional packet switchedsignal PS1.

Further, from the additional packet switched signal PS1 the processingapplication may derive authentication information about the networkservice NS, which enables the processing application HA to check theauthentication of the network service NS. In this manner, the user ofthe user terminal 5 can be sure of the identity of the network service3.

Finally, the data of the additional packet switched signal PS1 maycontain additional information which indicates the “reason” that thenetwork service NS requests the call to be answered automatically by theuser terminal 5.

The information comprised in the signal PS1 for at least one ofidentification, authentication and “reason” allows the processingapplication HA to apply a services filter FL on which network servicesare allowed to be answered automatically.

The services filter FL comprises data that are associated with the abovementioned information within the additional packet switched signal PS1for identification and/or for authentication purposes of the networkservice NS that transmitted or generated the signal PS1.

The services filter FL may be user-defined by means of e.g., an(possibly GUI-based) application on the user terminal 5. A user may usethe application to define one or more network services NS for whichhe/she allows the user terminal 5 to automatically answer an incomingcall. The application is capable of defining services filtering datawhich are accessible by the processing application HA for use during theprocess of determining if an automatic answer may be generated for anincoming call. The services filtering data are typically stored in amemory associated with the services filter FL.

In one embodiment, the user terminal 5 is arranged to process both theCS-alert signal CS1 and the additional packet switched signal PS1automatically, without notifying the user about the incoming message(i.e., have a silent alerting pattern). Carrying out this process may befor example be done by using applications for mobile terminals such asSIM Application Toolkit (SAT) and MExE. The processing application HAmay use an application programming interface such as J2ME. The skilledperson will however appreciate that alternative protocols andprogramming environments may be equally suitable.

Depending on the actual nature of the incoming call (and itsreliability), the present invention may allow the combination ofCS-alert signal CS1 and additional packet switched signal PS1 to begenerated by either the network service NS or the A-terminal of party A.

FIG. 5 shows a signal flow in accordance with the answering method ofthe present invention.

In this embodiment, the combination of CS-alert signal CS1 andadditional packet switched signal PS1 is generated by the networkservice NS on the network 3.

The call-setup is initiated by an A-terminal 6, which transmits CS-alertsignal (or in general, a CS-call setup) CS1 to the network 3. In thenetwork 3 a network service NS generates the additional packet switchedsignal PS1, which is transmitted to the user terminal 5 (or B-terminal5, not shown in detail) in combination with the CS-alert signal CS1. Asmentioned above, the CS-alert signal CS1 may be altered in that a silentalerting pattern is sent to the user terminal 5.

As explained before, the user terminal 5 will generate an automaticanswer (CS answer CS2) based on the information received in thecombination of CS-alert signal CS1 and additional packet switched signalPS1. The CS answer CS2 is transmitted to the network 3 and theA-terminal 6 to establish a speech communication 7.

FIG. 6 shows a further signal flow in accordance with the answeringmethod of the present invention.

In this embodiment, the combination of CS-alert signal CS1 andadditional packet switched signal PS1 is generated by the A-terminal 6.

The CS-alert signal CS1 and the additional packet switched signal PS1are both generated by an A-terminal 6 and transmitted over the network 3to the user terminal 5. The network 3 in this case appears transparentfor both the CS1 and PS1 signals. It is noted that the CS-call-setup orCS-alert signal CS1 generated by the A-terminal 6 may comprise a silentalerting pattern.

As explained before, the user terminal 5 will generate an automaticanswer (by means of CS answer CS2) based on the information received inthe combination of CS-alert signal CS1 and additional packet switchedsignal PS1. The CS answer CS2 is transmitted to the network 3 and to theA-terminal 6 to establish speech communication 7.

FIGS. 7 a, 7 b 7 c shows still further signals flow in accordance withthe answering method of the present invention.

In the embodiment of FIG. 7 a, the user terminal 5 receives an incomingcall with a CS-alert signal CS1 in combination with an additionalcircuit switched signal CS3 from a network service NS on network 3.

A network service NS generates the CS-alert signal CS1 and, in addition,a network-induced answer signal CS3.

The network-induced answer signal CS3 is a signal in the CS-domain.

The CS alert signal CS1 is guided to the CS-telephony device CS0. The CSalert signal CS1 will have an interaction with the finite state machineFSM as described above with reference to FIGS. 1 and 2. The finite statemachine FSM will change its state to the “call received” state 20 (ifnot busy).

The finite state machine FSM is arranged to expect the additionalcircuit switched signal CS3 in conjunction with the receipt of theCS-alert signal CS1. The finite state machine FSM is arranged to derivefrom the CS-alert signal CS1 that such an additional network-inducedanswer signal as CS3 is to be expected.

While expecting the additional circuit switched signal CS3, the finitestate machine FSM may be arranged to postpone generation of an alarm(audible, visible or tactile) for the user for a predetermined intervalof time in which the additional circuit switched signal (ornetwork-induced answer signal) CS3 may be received at the user terminal5.

Also, it is feasible that the additional circuit switched signal CS3arrives before the CS-alert signal CS1, but is withheld until arrival ofthe corresponding CS-alert signal CS1.

After receipt, the additional circuit switched signal CS3 is also guidedto the finite state machine FSM. The additional circuit switched signalCS3 may contain at least answering-related data that relate to the“ongoing” CS alert signal CS1.

The finite state machine FSM may be arranged to determine from theadditional circuit switched signal CS3 if the network service requeststhat an automatic answer by the user terminal 5 is executed.

If an automatic answer is requested, the finite state machine FSMchanges it's state by transition from the “call received” state 20through intermediate state(s) 25 to the “active” 30 state, and transmitsthe CS answer CS2 to the network 3 (network service NS).

Next, speech communication 7 can be initiated.

In the embodiment of FIG. 7 a, the user terminal 5 receives an incomingcall with a CS-alert signal CS1 in combination with an additionalcircuit switched signal CS3 from a network service NS on network 3.

A network service NS generates the CS-alert signal CS1 and, in addition,the additional circuit switched signal CS3, both transmittable over thecircuit switched bearer service.

In the embodiment of FIG. 7 b, the user terminal 5 receives an incomingcall with a CS-alert signal CS1 in combination with an additionalcircuit switched signal CS3 from a call initiating A-terminal 6.

The A-terminal 6 which initiates the incoming call for the user terminal5 generates the CS-alert signal CS1 and, in addition, the additionalcircuit switched signal CS3, both over the circuit switched bearerservice.

The network 3 in this case appears transparent for both the CS1 and CS3signals. It is noted that the CS-call-setup or CS-alert signal CS1generated by the A-terminal 6 may comprise a silent alerting pattern.

Again, as described above with reference to FIG. 7 a, the finite statemachine FSM is arranged for determining from the network-induced answersignal CS3 if the network service requests that an automatic answer bythe user terminal 5 is executed.

If so, the finite state machine can change it's state by transition fromthe “call received” state 20 through the intermediate state(s) 25 to the“active” 30 state, and transmit the CS answer CS2 to the network 3 (andthe A-terminal 6). Next, speech communication 7 between A-terminal 6 anduser terminal 5 can be initiated.

In the embodiment of FIG. 7 c, the user terminal 5 receives an incomingcall with a CS-alert signal CS1 in combination with an additional packetswitched signal PS1 which comprises an invitation signal IS1.

The additional packet switched signal PS1 over the packet switchedbearer service may be generated by a network service NS or by a callinitiating A-terminal 6 as explained above with reference to FIG. 5 andFIG. 6, respectively.

The processing application HA is arranged to extract the invitationsignal IS1 from the additional packet switched signal PS1 and totransmit the invitation signal IS1 to the further device D0. The furtherdevice D0 is arranged for processing the invitation signal IS1 by someGUI based application, which now presents information related to theincoming call to the user. After receiving a feed-back signal FS forthis information from the user, the user terminal transmits the(information related to the) feed-back signal SF in packet switchedformat back to the network service NS over the PS bearer service.

The network service NS is arranged for recognizing the feed-back signalfrom the user terminal 5. Accordingly, the network service NS nowresponds by sending a induced CS-answer signal CS3 over the circuitswitched bearer service to the user terminal 5 to inform it CS0 aboutthe user interaction with packet switched signal PS1, comprising theinvitation signal IS1. The finite state machine FSM receives thenetwork-induced CS-answer CS3 and changes it's state to the “active”state 30. Accordingly, the CS-telephony based device CS0 transmits a CSanswer CS2 to the network 3 (network service NS and/or A-terminal 6).

If required, speech communication 7 may now be established.

FIG. 8 shows a signaling diagram for a further embodiment of theanswering method of the present invention.

In this embodiment similar to the embodiment shown in FIG. 5, thecombination of CS-alert signal CS1 and additional packet switched signalPS1 is generated by the network service NS on the network 3.

The call-setup is initiated by an A-terminal 6, which transmits aCS-alert signal CS1 to the network 3. In the network 3 a network serviceNS generates the additional packet switched signal PS1 over the packetswitched bearer service, which is transmitted to the user terminal 5 (orB-terminal 5, not shown in detail) in combination with the CS-alertsignal CS1. As mentioned above, the CS-alert signal CS1 may be alteredin that a silent alerting pattern is sent to the user terminal 5.

The additional packet switched signal PS1 comprises a ring-delay signalRS which contains information on a number of rings or time intervalbefore the automatic CS-answer CS2 is to be transmitted to the network3. The processing application HA processes the additional packetswitched signal PS1 and extracts the ring-delay signal RS information.Through the connection 40 the processing application HA sends (theinformation relating to) the ring-delay signal RS to the finite statemachine FSM which determines from the received ring information afterhow many rings (or when) to change from the “call received” state 20 tothe “active state” 30 and to transmit the CS-answer signal CS2 to thenetwork 3.

As explained before, the CS-answer CS2 is transmitted to the network 3and the A-terminal 6 to establish a speech communication 7.

FIG. 9 shows a CS-call state diagram in a further embodiment of theanswering method of the present invention.

In this embodiment of the invention, the user terminal 5 has givenprivilege to the A-terminal 6 to “break-in” into a conversation during apossibly ongoing first other call between the user terminal 5 andanother A-terminal. In this situation, the present invention may providea “(network-induced) forced call hold” as explained below.

The principle of “call hold” is described in GSM TS 04.83 v.7.0.1.Chapter 2.1.5 of GSM TS 04.83 describes states for “call hold”. The“call hold” states are considered in this document as auxiliary states,that are part of the general “active” state 30.

The privileged A-terminal 6 sets up a call to the user terminal 5 andincludes a “forced call hold” instruction in the call set up, or anetwork service NS may provide the “forced hold instruction” on behalfof the privileged A-terminal 6. This “forced call hold” instruction istransported as the additional packet switched signal PS1 through thebearer service in the PS domain. This “forced call hold” instruction mayhave the effect that when received by the user terminal 5, theprocessing application HA provides a hold signal or hold primitive HSover connection 40 to the finite state machine FSM.

Depending on the actual state of the user terminal 5 when the call ofthe privileged A-terminal comes in, i.e., the “null” state 10 (=idle) orthe “active” state 30 (=busy), the finite state machine FSM mayinterpret the hold signal HS differently.

During the “null” state 10, the finite state machine FSM will changeit's state to the “call received” state 20 (as described above) and mayignore the “hold” signal (In this case, the incoming call can be handledby the party B as a normal call from the prior art). Alternatively, inaccordance with one or more of the embodiments as described above, thefinite state machine FSM may interpret the “hold” signal HS as a networkinduced instruction for automatically answering the incoming call andchange to the “active” state 30.

However, when the hold signal comes in at the finite state machine FSMduring an “active” state of the first other call, the finite statemachine FSM is arranged to change the state for that first other activecall to a “hold” state 45 (change indicated by arrow H1), and change thestate of the incoming call from the privileged A-terminal 6 to the“active” state (arrow H2).

After termination of the call from the privileged A-terminal 6, thefinite state machine restores it's state to the preceding state: thefirst other call on “hold” (in the “hold” state) is retrieved andrestored to the “active” state (arrow H3), or if no other call waspresent the state is changed to the “null” state.

Note that both the transfer (H1) of the other call from the “active”state 30 to the “hold” state 45 and the restoration (H3) of the othercall from the “hold” state 45 to the “active” state 30 may, per se, becarried out in accordance with the GSM TS 04.83 specification. Theadditional packet switched signal PS1 (a network-induced signal) inaccordance with the present invention instructs the user terminal 5 tocarry out either of both actions H1, H3.

The inclusion of the “forced call hold” may be done manually by party A.Alternatively, including the “forced call hold” may be doneautomatically by the A-terminal 6 by some recognition procedure for theB-number of the user terminal 5.

For example, the B-number of the user terminal 5 and an indication forapplication of “forced call hold” for that B-number may be stored in amemory of the A-terminal. When the B-number of the user terminal 5 iscalled, the A-terminal may use the data stored in the memory to transmitthe “forced call hold” instruction automatically.

Furthermore, the additional information (of the “forced call hold”instruction) in the additional packet switched signal PS1 can containreferences to announcements (audible on a speaker or visible on adisplay of the respective terminals) that must be presented to the userterminal 5 and/or the other A-terminal in the first other call.

For example, the party of the other A-terminal that is going to beplaced on “hold” may receive an appropriate announcement and the party Bof the user-terminal 5 that is going to be automaticallythrough-connected with the party of the privileged A-terminal 6 mayreceive an appropriate announcement. These announcements may differ fromone another. The announcements may be provided by a network service NSin response to an announcement signal in the PS domain from the userterminal 5.

The additional information in the additional packet switched signal PS1can also indicate to the B party's user terminal 5 that thenetwork-induced “forced call hold” should occur after a defined numberof rings (e.g. 3 rings). That enables the party B to answer the phone byitself, instead of “having it answered”.

Network-induced “call hold” can be a good extension to an application ofproviding spoken content during route navigation via the mobile phonewhile driving. When a driver expects route information (e.g. “next exiton the highway”), he also expects to receive this information in thecase that he has an ongoing phone conversation. So, the spoken routeinformation must automatically put the ongoing conversation on hold,possibly play the announcement(s), disconnect, and restore the originalconversation.

It is noted that the method for the user terminal 5 according to thepresent invention may be implemented in hardware and/or software. Incase of software the user terminal 5 comprises a processing unit andmemory, the memory being coupled with the processing unit. The userterminal 5 is capable of loading a computer program which implements themethod as described above. After loading of the computer program, theprocessing unit of the user terminal 5 is arranged for executing theprogram so as to obtain the functionality as described above.

Similarly, software programs may be used within the network service 3and/or the call initiating A-terminal 6 in order to obtain thefunctionalities as described above with reference to the network serviceNS and the A-terminal 6, respectively.

The present invention can also be implemented in a variety ofapplications for the user terminal 5.

In a first CS-based application the user terminal 5 is arranged forreceiving spoken content of a guided tour. The user terminal 5 may beany suitable mobile communication device in accordance with any one ofthe embodiments.

Each time when new content becomes available (e.g. in reaction to alocation of the user terminal 5) the CS-based application initiates acall to the user terminal 5 by means of the additional packet switchedsignal PS1. Each call is automatically answered without interaction bythe user, in accordance with one or more of the embodiments describedabove.

In another application, the user terminal 5 is arranged to have afunction of a babyphone. The user terminal 5 may be located in a roomwith a child for example, a baby or toddler. Any call to the userterminal 5 results in a connection for recording sound from the room.The call contains the additional packet switched signal PS1 forautomatically answering the call, and may also contain an instructionfor a silent alerting pattern.

The babyphone can be embodied by any one of the embodiments of a userterminal as described above, in which the user terminal is arranged forcommunication over a telecommunications network which comprises at leasta CS-telephony device CS0 for processing CS-based telephony signals CS1,CS2, the CS-based telephony signals being received and transmitted overa circuit switched bearer service. The user terminal is arranged forreceiving an additional answer-related signal PS1; CS3, with theadditional answer-related signal being associated with an incomingCS-alert signal CS1 of an incoming call. Further, the user terminal isarranged for transmitting a response signal or CS-answer signal CS2 overthe circuit switched bearer service in response to information comprisedin, or derived from, the additional answer-related signal.

In a further application, the present invention provides thenetwork-induced call hold as described above. An A-terminal 6 calls theuser terminal 5 of the present invention. The user terminal is busy in acall to another terminal. The A-terminal 6 is privileged to “break in”in the ongoing call as explained before. The user of the A-terminalreceives the “busy” signal and may by giving an instruction on theA-terminal 6 force the user terminal 5 to hold the other call andconnect to the A-terminal in speech communication. The instructiontriggers the generation of the additional packet switched signal PS1which causes the user terminal 5 to respond to the A-terminal 6 when PS1has been received. The other call is put on hold. A message may bepresented to the party of the other call that the call is put on hold.

In still another application, the present invention provides thenetwork-induced “call hold” as described above. An A-terminal 6 callsthe user terminal 5 of the present invention. The user terminal 5 isbusy in another call to another terminal. The A-terminal 6 is privilegedto “break in” in the ongoing call as explained before. In this case, nouser interaction on the A-terminal is required. The busy signal is nottransmitted to the party of the A-terminal 6. The additional packetswitched signal PS1 may be sent directly with the call setup signal, ormay be generated by a network service NS when a busy signal is detectedfor the user terminal 5. The user terminal 5 responds to the A-terminal6, the other call is put on “hold”. A message may be presented to theparty of the other call that the call is put on “hold”.

Although specific embodiments of the invention have been described, itshould be understood that the embodiments are not intended to limit theinvention. The invention may embody any further alternative,modification or equivalent, only limited by the scope of the appendedclaims.

1. A user terminal for communication over a telecommunications network,the user terminal comprising: a circuit-switched (CS) telephony deviceconfigured to receive and transmit CS-based telephony signals over acircuit-switched bearer service, wherein the CS telephony devicereceives a CS-alert signal from the network for an incoming call; apacket-switched (PS) data processing device configured to receive over apacket switched bearer service, a PS signal within a predeterminedinterval of time following receipt of the CS-alert signal by the CStelephony device, wherein the PS signal is associated with the CS-alertsignal and includes information indicating an answering mode for theuser terminal; wherein the PS data processing device is configured topass a control signal to the CS telephony device causing the CStelephony device to switch to an automatic answering mode; and whereinthe CS telephony device is configured to transmit a CS-answer signal tothe network in response to the control signal.
 2. The user terminalaccording to claim 1, wherein the CS-telephony device comprises a finitestate machine which in response to the information received in the PSsignal, is configured to change a state of the user terminal to anactive state for the incoming call and for transmitting the CS-answersignal.
 3. The user terminal according to claim 2, wherein the PS dataprocessing device comprises: a processing application for processing thePS signal, the processing application being capable of deriving theinformation from the PS signal; wherein an output of the processingapplication is connected to an input of the finite state machine fortransmitting the control signal to the finite state machine; and whereinthe finite state machine is configured to receive the control signal andto change the user terminal's state in response to the received controlsignal.
 4. The user terminal according to claim 3, wherein the controlsignal is a hold signal for causing the finite state machine to changean active state of another ongoing call to a hold state and to put theincoming call into the active state.
 5. The user terminal according toclaim 4, wherein the finite state machine is configured to provide anacceptance signal for the incoming call to the CS-telephony device, andthe CS-telephony device is further configured to transmit to a secondterminal involved in the other ongoing call and to a third terminaloriginating the incoming call, a message relating to the change of callstates for the ongoing call and the incoming call, respectively.
 6. Theuser terminal according to claim 3, wherein the information in the PSsignal also includes a ring delay signal for causing the finite statemachine to determine a time interval after which to change to the activestate for the incoming call and to transmit the CS-answer signal.
 7. Theuser terminal according to claim 3, further comprising: a further devicefor providing at least one locally executable application; and wherein afurther output of the processing application in the PS data processingdevice is connected to an input of the further device, the processingapplication being configured to extract an invitation signal from the PSsignal and to transmit the invitation signal to the further device. 8.The user terminal according to claim 7, wherein the locally executableapplication is configured to: process the invitation signal and topresent information related to the incoming call to a user of the userterminal; receive a user feed-back signal; and cause the PS dataprocessing device to transmit a further feed-back signal to the networkover the packet switched bearer service.
 9. The user terminal accordingto claim 8, wherein the CS-telephony based device is further configuredto receive an additional CS signal in response to the transmission ofthe feed-back signal, and the finite state machine is configured tochange the user terminal's state to the active state for the incomingcall in response to the receipt of the additional CS signal.
 10. Anetwork service on a telecommunications network the network servicecomprising: a circuit-switched (CS) bearer service for receiving andtransmitting CS-based telephony signals, wherein the CS bearer serviceis configured to send a CS-alert signal of an incoming call to a userterminal; and a packet-switched (PS) bearer service configured to send aPS signal to the user terminal within a predetermined interval of timefollowing the CS-alert signal, wherein the PS signal is associated withthe CS-alert signal and the PS signal includes information indicating ananswering mode for the user terminal, wherein the PS signal causes theuser terminal to switch to an automatic answering mode and to transmit aCS-answer signal over the CS bearer service.
 11. A call initiatingterminal for communication over a telecommunications network, the callinitiating terminal comprising: a circuit-switched (CS) telephony devicefor processing CS-based telephony signals, the CS-based telephonysignals being received and transmitted over a CS bearer service, whereinthe CS telephony device transmits a CS call-setup signal to the networkto set up an outgoing call to a user terminal; and a packet-switched(PS) processing device configured to transmit a PS signal over a PSbearer service within a predetermined interval of time following the CScall-setup signal, wherein the PS signal is associated with thetransmitted CS call-setup signal, and includes information causing theuser terminal to switch to an automatic answering mode and to transmit aCS-answer signal to the network in response to the PS signal.
 12. Amethod for communication over a telecommunications network, the methodcomprising: receiving and transmitting by a user terminal,circuit-switched (CS)-based telephony signals over a CS bearer service,wherein the user terminal receives a CS-alert signal from the networkfor an incoming call; receiving by the user terminal, a packet-switched(PS) signal over a packet switched bearer service, the PS signal beingassociated with the CS-alert signal and being received within apredetermined interval of time following receipt of the CS-alert signal,wherein the PS signal includes information indicating an answering modefor the user terminal; switching by the user terminal to an automaticanswering mode in response to the information received in the PS signal;and transmitting by the user terminal, a CS-answer signal over thecircuit switched bearer service.
 13. The method according to claim 12,wherein the step of switching to an automatic answering mode includeschanging by a finite state machine in the user terminal, a state for theincoming call to an active state.
 14. The method according to claim 13,further comprising, in response to receiving the information in the PSsignal: changing by a finite state machine in the user terminal, anactive state of another ongoing call to a hold state; putting theincoming call into the active state; and transmitting messages relatingto the change of call states to terminals involved in the other ongoingcall and the incoming call.
 15. The method according to claim 12,further comprising: extracting by the user terminal, an invitationsignal from the PS signal; processing the invitation signal by the userterminal to present information related to the incoming call to a user;receiving by the user terminal, a user feed-back signal; transmitting aPS feed-back signal from the user terminal to the network, in responseto the received user feed-back signal; and receiving by the userterminal, an additional CS signal in response to the transmission of thePS feed-back signal.
 16. The method according to claim 12, furthercomprising: sending the CS-alert signal from the network to the userterminal in response to a location of the user terminal; sendingadditional information in the PS signal related to the location of theuser terminal; and answering the call by the user terminal withoutinteraction by a user and presenting to the user, the additionalinformation received in the PS signal.